1. Field of the Invention
The present invention relates to a case that houses, for example, a disc medium or a reel around which recording tape such as magnetic tape is wound.
2. Description of the Related Art
Recording tape such as magnetic tape is used as an external recording medium for computers and the like to back up information. A recording tape cartridge, which houses within a case a single reel around which is wound recording tape whose housing space during storage is small and on which a large volume of information can be recorded, is employed.
In the recording tape cartridge, the single reel, around which is wound the recording tape, is rotatably accommodated within the case, which is formed by joining an upper case that serves as a base or a cover with a lower case that serves as a cover or a base, with both the upper case and the lower case being made of a resin material. An opening, which is opened and closed off by a door and through which the recording tape is pulled out, is formed in the case.
When the recording tape cartridge is to be used, the recording tape cartridge is loaded into a drive device, and within the drive device, the door is operated, the opening is opened, and the recording tape cartridge is precisely positioned. In this state, recording and playback of information is carried out as the recording tape is pulled out from the case and taken up at a take-up reel in the drive device.
In large-scale backup systems, the recording tape cartridge is generally used in a library device that houses plural recording tape cartridges and automatically (without the intervention of human hands) loads the recording tape cartridges into and removes the recording tape cartridges from the drive device. In such a library device, the recording tape cartridges are housed in a state in which they are respectively positioned in holders, and when the recording tape cartridges are to be used, the recording tape cartridges are conveyed and loaded into the drive device while being held by, for example, a chucking mechanism. After being used, the recording tape cartridges are conveyed and housed in the holders while being held by the chucking mechanism.
In the recording tape cartridge described above, plural recesses or bottomed holes (referred to below as recesses) are disposed in the case in order for the recording tape cartridge to be positioned (i.e., subjected to regulation of orientation thereof) in the drive device and in the holder, and in order for the recording tape cartridge to be reliably held by the chucking mechanism. The directions in which the recesses open, the dimensional shape of the recesses, and the positions at which the recesses are disposed respectively differ depending on their function (purpose for which they are used).
On the other hand, in drive devices and library devices, there are instances where the ways in which the recording tape cartridge is positioned, held, and conveyed differ depending on the model and specifications of the devices. Therefore, it becomes necessary to dispose more recesses in the case in order for the recording tape cartridge to be adapted and adequately accommodated by such plural types (specifications) of drive devices and library devices. Also, in order to prevent mistaken use of the recesses (e.g., the occurrence of a state where positioning members or conveyance rollers of a non-corresponding library device are inserted into the recesses and obstruct correct operation), it may be necessary, depending on the recesses, that the directions in which the recesses open, the dimensional shape of the recesses, and the positions at which the recesses are disposed are regulated according to their relation with other recesses.
There are also instances where recesses or bottomed holes, whose being opened at an outer surface of the case is not allowed and thus which open only to the side of the case (to an outer surface of a peripheral wall of the case), are disposed. In these instances, as long as the recesses are formed by joining an upper recess, which is disposed in a peripheral wall of the upper case and opens sideward and downward, with a lower recess, which is disposed in a peripheral wall of the lower case and opens sideward and upward, there arise no problems when the upper case and the lower case are removed from molds at the time of molding. However, when the recess is not disposed at the attaching wall of the upper/lower case at which the upper case is attached to the lower case, i.e., when the recess is positioned distanced from the attaching walls of the upper and lower cases, there arises a problem.
Namely, when recesses that open only sideward are to be disposed in the peripheral wall of the lower case serving as the base, it is necessary to use a slide core when molding the recesses because undercuts are to be formed in the lower case, which results in the mold structure becoming complicated and costs becoming high.
There arise similar problems when recesses that open only in the outer surface of the peripheral wall are to be disposed with respect to cases in general that are formed by joining the cover to an open end of the peripheral wall of the base, such as cases for two-reel recording tape cartridges disposed with a reel for winding off the magnetic tape and a reel for taking up the magnetic tape, and cases for disc cartridges that rotatably house disc media.